I have the following problem with tikz: I want to draw some circular arcs, but unfortunately these arcs have degrees which pass the 360° line. I would like to be able to draw these arcs with one single command, but I can't figure out how to do it. If I give the arc commands two angles where the first is larger than the second, tikz will simply interchange the angles before drawing them.

Instead of defining your command in that way I would do the following. Not only will it automatically do it the right way, from your defined angles, but it will also make the middle connection more pretty.